Patriots quarterback Tom Brady underwent a second procedure on his injured left knee Wednesday to clear out an infection, according to a source close to the QB. Brady had the initial surgery Oct. 6 in Los Angeles. Doctors said the procedure went well, but Brady began to feel ill this week because of the infection. "This can happen to anyone having a surgery, but it's a relatively rare occurrence after knee procedures," Dr. Nicholas DiNubile said. "The earlier you recognize and treat it - that's surgery and antibiotics - the less likely you're going to have problems down the line. The best-case scenario is that they got it early, and if everything goes right, he would be back at the same time as was expected."